<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group name="breadcrumb">
      <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path">
        <span v-if="item.redirect==='noRedirect'||index==levelList.length-1" class="no-redirect">{{
            item.meta.title
          }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script lang="ts">
import {defineComponent, ref,watch} from "vue";
import {useRoute, useRouter} from "vue-router";
import * as pathToRegexp from 'path-to-regexp'

export default defineComponent({
  setup() {
    const route = useRoute();
    const router = useRouter();
    const levelList = ref([])

    function getBreadcrumb() {
      // only show routes with meta.title
      let matched = route.matched.filter(item => item.meta && item.meta.title)
      const first = matched[0]

      if (!isDashboard(first)) {
        matched = [{path: '/dashboard', meta: {title: '首页'}}].concat(matched)
      }

      levelList.value = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
    }

    function isDashboard(route) {
      const name = route && route.name
      if (!name) {
        return false
      }
      return name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
    }

    function pathCompile(path) {
      const {params} = route
      var toPath = pathToRegexp.compile(path)
      return toPath(params)
    }

    function handleLink(item) {
      const {redirect, path} = item
      if (redirect) {
        router.push(redirect)
        return
      }
      router.push(pathCompile(path))
    }

    function routeProcess(routePath: any) {
      // if you go to the redirect page, do not update the breadcrumbs
      if (routePath.startsWith('/redirect/')) {
        return
      }
      getBreadcrumb()
    }

    getBreadcrumb()


    watch(()=>route.path?route.path:'', routeProcess)
    return {
      levelList,
      handleLink
    }
  }
})
</script>

<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 50px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
